Integrated Kinematic Machining Error Compensation for Impeller Rough Tool Paths Programming in a Step-Nc Format Using Neural Network Approach Prediction

2021 ◽  
pp. 144-170
Author(s):  
Hacene Ameddah
Keyword(s):  
Neural Network ◽  
Research Work ◽  
Free Form ◽  
Cnc Machine ◽  
Rough Machining ◽  
Neural Network Approach ◽  
Tool Paths ◽  
Nc Program ◽  
Finishing Process ◽  
G Code

The most important components used in aerospace, ships, and automobiles are designed with free form surfaces. An impeller is one of the most important components that are difficult to machine because of its twisted blades. This research book is based on the premise that a STEP-NC program can document “generic” manufacturing information for an impeller. This way, a STEP-NC program can be made machine-independent and has an advantage over the conventional G-code-based NC program that is always generated for a specific CNC machine. Rough machining is recognized as the most crucial procedure influencing machining efficiency and is critical for the finishing process. The research work reported in this chapter focuses on introduces a fully STEP-compliant CNC by putting forward an interpolation algorithm for non uniform rational basic spline (NURBS) curve system for rough milling tool paths with an aim to solve the problems of kinematic errors solutions in five axis machine by neural network implementation.

scholarly journals Generation Method of Cutting Tool Paths for High-Speed and High-Quality Machining of Free-Form Surfaces

2021 ◽  
Vol 15 (4) ◽  
pp. 521-528
Author(s):  
Yuki Takanashi ◽  
Hideki Aoyama ◽  
Song Cheol Won ◽  
◽  
Keyword(s):  
High Speed ◽  
Processing Time ◽  
Free Form ◽  
Machining Accuracy ◽  
Cnc Machine ◽  
Block Processing ◽  
Tool Paths ◽  
Nc Program ◽  
Straight Line ◽  
Free Form Surfaces

In general, NC programs for machining free-form surfaces using a computer numerical control (CNC) machine tool are generated using a computer-aided manufacturing (CAM) system. The tool paths (CL data) generated by a CAM system are approximated straight-line segments based on tolerance (allowable error). As a result, the tolerance affects the machining accuracy and time. If the tolerance is set to a small value, the lengths of the segments are shortened, and the machining accuracy is improved. The process in which a CNC machine tool reads and analyzes an NC program and controls the motors requires a minimum processing time of an NC program block (block-processing time). Therefore, if the lengths of the approximated straight-line segments are too small, it will be impossible to reach the indicated feed speed, and the machining time will be longer. In this study, by identifying the block-processing time of a CNC controller and deriving the appropriate length of the approximated straight-line segment based on the block-processing time, a CL data creation method that is capable of high-speed and high-accuracy free-form surface machining is proposed. In addition, experimental verification tests of the method are conducted.

Adaptive Tool Path Planning Strategy for 5-Axis CNC Machining of Free Form Surfaces

2019 ◽  
Author(s):  
Hrishikesh Mane ◽  
S. S. Pande
Keyword(s):  
Tool Path ◽  
Cnc Machining ◽  
Memory Storage ◽  
Free Form ◽  
Cnc Machine ◽  
Planning Strategy ◽  
Part Quality ◽  
Tool Paths ◽  
Path Topology ◽  
Free Form Surfaces

Abstract This paper presents a curvature based adaptive iso-parametric strategy for the efficient machining of free form surfaces on 5-axis CNC machine using the flat end mill tool. One iso-parametric boundary of the surface is selected as the initial tool path. Set of cutter contact (CC) points are chosen adaptively on the initial tool path considering desired profile tolerance. Adjacent iso-parametric tool paths are computed adaptively based on the scallop height constraint unlike the traditional iso-parametric approach. The path topology is post-processed to generate the part program for 5-axis CNC machine in ISO format. The system was rigorously tested for various case studies by comparing the results with the traditional 5-axis iso-parametric tool path strategy, iso-scallop strategy and iso-planar strategy of a commercial software. Our system was found to generate efficient tool paths in terms of part quality, productivity and memory storage compared to the conventional strategies.

Determination of Isosteric Heat and Entropy of Sorption of Air Dried Sheet Rubber Using Artificial Neural Network Approach

2014 ◽  
Vol 541-542 ◽  
pp. 374-379 ◽  
Author(s):  
Kiattisak Suntaro ◽  
Supawan Tirawanichakul ◽  
Yutthana Tirawanichakul
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Moisture Content ◽  
Water Activity ◽  
Research Work ◽  
Isosteric Heat ◽  
Neural Network Approach ◽  
Heat Of Sorption ◽  
Artificial Neural

Equilibrium moisture contents (EMC) of air dried sheet (ADS) rubber were determined by commonly gravimetric-static method with saturated salt solution among surrounding temperatures of 40-70°C correlated to water activity (aw) ranges between 0.10 and 0.9. The experimental results was analyzed by 5 commonly EMC model. The results showed that equilibrium moisture content of ADS rubber decreased with increase of surrounding temperature at constant water activity and the simulated data using Chung-Pfost model has a good relation to experimental data with R2, RMSE and χ2 equal 0.9565, 0.0235 and 0.0006, respectively. However some physical property of ADS rubber sample affects to evaluate EMC modeling. Due to avoid this effect, thus the aim of this research work was to determine EMC value by using Artificial neural network (ANN) method and also evaluate the isosteric heat of sorption by following the Clausius-Clapeyron equation. The results showed that simulated results using ANN approach has relatively high accuracy compared to common EMC model. Finally determination of isosteric heat of sorption and entropy of sorption of ADS rubber were carried on. The results stated that the enthalpy and entropy of heat sorption was power function and polynomial function of moisture content respectively. These two parameters of ADS rubber can be used for prediction suitable storage condition and drying condition for ADS rubber drying in the near future work.

A Generic Multi-Axis Post-Processor Engine for Optimal CNC Data Creation and Intelligent Surface Machining

2017 ◽  
Vol 261 ◽  
pp. 463-469
Author(s):  
Nikolaos A. Fountas ◽  
Constantinos I. Stergiou ◽  
Nikolaos M. Vaxevanidis ◽  
Redha Benhadj-Djilali
Keyword(s):  
Internal Source ◽  
Machining Parameters ◽  
Cnc Machine ◽  
Tool Selection ◽  
Surface Machining ◽  
Source Codes ◽  
Tool Paths ◽  
Discretization Step ◽  
G Code ◽  
Manufacturing Resource

This paper focuses on the development of a multi-axis post-processor engine with a curvature-based feed adaptation module, capable of extracting generic CNC data for high precision machining. The motivation of this work stems from the drawback of standard and commercial post-processors to modify their internal source codes so as to be implemented to newly-developed functions which integrate modern CNC units. The multi-axis post-processor proposed in this work operates as a stand-alone function of an artificial intelligent module that optimizes machining parameters for standard swept cut multi-axis surface tool-paths. The post-processor developed receives APT source files previously been optimized by means of a genetic algorithm that handles cutting tool selection; radial cut engagement; maximum discretization step; lead and tilt angles. The algorithm optimizes the aforementioned machining parameters towards the minimization of the number of cutter locations found in a specific APT source file as well as the surface machining error as a combined effect of chordal deviation and scallop height. The final APT output is then properly handled by the post-processor engine so as to extract the final ISO code for a double-pivoted head 5-axis CNC machine and compute optimal values for feed rate in each NC block considering the interpolation error and curvature analysis given the surface properties. To simulate and verify our proposals, the MAZAK Vortex 1000 gantry-type 5-axis CNC machine tool equipped with a Fanuc 15i CNC unit has been selected as the manufacturing resource corresponding to the final CNC output that the proposed post-processor computes. A benchmark sculptured part is created and used for the virtual material removal simulation in CATIA® V5 R18. For that part, both the proposed post-processor engine and a commercially available post-processor were employed to extract G-code data whilst it was shown that identical outputs were obtained.

A Framework for a Feature Based Machining Using Macro

2011 ◽  
Vol 110-116 ◽  
pp. 1711-1715 ◽  
Author(s):  
M. Al’Hapis ◽  
A. Razak ◽  
Ahmad Zakaria
Keyword(s):  
User Interface ◽  
Graphical User Interface ◽  
Manufacturing Industry ◽  
Research Work ◽  
Setup Time ◽  
Machining Efficiency ◽  
Cnc Machine ◽  
Nc Program ◽  
Machining System ◽  
Feature Based

This paper describes a research work to explore the utilization of macros in an effort to improve an overall machining efficiency. Latest models of CNC machine are equipped with many functions and resulting difficulty in creating NC program. Feature based machining is optimizing the capabilities of CNC machine. A novel framework of a feature based machining system using macros is discussed in this paper by applying some normally used features and work material in manufacturing industry. Experiments has been conducted in proving its functionality. This system found enable to reduce pre-machining setup time and easy to used. Lastly, a graphical user interface is proposed.

scholarly journals Error Investigation for Free Form Surfaces in Bezier Techniques

2018 ◽  
Vol 24 (12) ◽  
pp. 1-11
Author(s):  
Ahmed A.A. Duroobi ◽  
Safaa Kadhim Ghazi ◽  
Rasha Ramiz Alyas
Keyword(s):  
Control Point ◽  
Machining Process ◽  
Free Form ◽  
Similar Degree ◽  
Cnc Machine ◽  
Virtual Machining ◽  
Machining Process Simulation ◽  
Interior Data ◽  
G Code ◽  
Free Form Surfaces

Surface modeling utilizing Bezier technique is one of the more important tool in computer aided geometric design (CAD). The aim of this work is to design and implement multi-patches Bezier free-form surface. The technique has an effective contribution in technology domains and in ships, aircrafts, and cars industry, moreover for its wide utilization in making the molds. This work is includes the synthesis of these patches in a method that is allow the participation of these control point for the merge of the patches, and the confluence of patches at similar degree sides due to degree variation per patch.  The model has been implemented to represent the surface. The interior data of the desired surfaces designed by MATLAB software have been transformed to UG-NX8 software to get the machining process simulation and G-code programs for the model, as well as a virtual machining process has been simulated to show the machining pitfalls, using CIMCO edit software. The sample has been machined using 3-axis vertical CNC machine. Finally, the sample has been measured using (CMM inspection) and it’s found that the average of error (0.144 mm).

A Reliable and Efficient Approach to Numerically Controlled Programming Optimization for Multiple Largest Tools Cutting Blisks Patch by Patch in the Blisks' Four-Axis Rough Machining

2017 ◽  
Vol 139 (9) ◽  
Author(s):  
Zhiyong Chang ◽  
Jinan Wen ◽  
Zezhong C. Chen ◽  
Dinghua Zhang
Keyword(s):  
Large Diameter ◽  
Small Diameter ◽  
Surface Patch ◽  
Free Form ◽  
Cnc Machine ◽  
Rough Machining ◽  
Cnc Machines ◽  
End Mills ◽  
Five Axis ◽  
Free Form Surfaces

As an important component of gas turbine engines, a blisk (or an axial compressor) is complex in shape. The pressure and suction surfaces of the blisk blades are designed with free-form surfaces, and the space (or the channel) between two adjacent blades varies significantly. Thus, some blade patches can be machined with large-diameter cutters, and some patches have to be cut with small-diameter cutters. Usually, the blisk's material is high-strength stainless steel, titanium alloy, or difficult-to-cut material. The cutting force and temperature in roughing the blisks are high, and thus, the machine tool should be rigid and the cutters should be as large as possible. Therefore, the best industrial practice of rough-machining the blisks is to use multiple largest solid and indexable end-mills to cut them patch by patch on a four-axis computer numerically controlled (CNC) machine. The reasons are (a) four-axis CNC machines are more rigid than five-axis CNC machines, (b) multiple largest cutters are used for higher cutting speeds and feed rates and for less machining time and longer tool life, and (c) if indexable end-mills can be used, the tooling costs are further reduced. For the blisk finishing, a small cutter is often used on a five-axis CNC machine, which is not a topic of this work. However, due to complex shape of the blades, it is quite difficult to automatically optimize the blade surface partition so that each surface patch can be cut with a largest cutter in four-axis blisk rough machining. In the conventional way, numerically controlled (NC) programmers often employ small-diameter solid end-mills and plan their paths to cut the blades layer by layer in four-axis milling. Unfortunately, the machining efficiency of this way is low, and the end-mills wear out quickly. This work establishes a theoretical and completed solution. A simplified optimization model of the largest allowable diameter of the theoretical cutter at a cutter contact (CC) point is established, and an efficient and reliable solver is proposed. The blade surfaces are automated partitioned for largest cutters to the surfaces patch by patch in four-axis rough machining. This approach is efficient and reliable, and it is viable in theory and practical in industry.

Sign in / Sign up

Export Citation Format

Share Document